ES2955308T3 - Priming valve to induce proper pressure and flow profile and improve sensor availability - Google Patents

Abstract

A priming valve includes a fluid flow path, a fluid inlet configured to couple to a fluid outlet of a fluid channel including at least one sensor configured to characterize at least one attribute of a fluid, a fluid outlet , a valve seat and a connector. . The connector engages the valve seat to prevent fluid flow through the fluid flow path. The connector is configured to move relative to the valve seat in response to a threshold pressure within the fluid flow path to allow fluid to flow through the fluid flow path. A flow sensor subassembly for detecting the flow of a fluidic medication may include a priming valve and at least one sensor of a fluid port configured to characterize at least one attribute of a fluid within a deliverable fluid source. One method of preparing a fluid sensor may use a priming valve. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Priming valve to induce a suitable pressure and flow profile and improve the availability of a sensor BACKGROUND OF THE INVENTION

1. Description field

[0001] The present description relates, generally, to a priming valve for a fluid sensor and to a flow sensor system comprising said valve. More particularly, the present disclosure relates to a flow sensor system and a method of preparing a flow sensor of the flow sensor system for characterizing at least one attribute of a fluid that is desired to be detected by the flow sensor.

2. Description of the related art

[0002] There is a need to improve volumetric precision in bolus delivery using a medical device. It would be advantageous to provide a flow sensor system having a flow sensor with improved flow measurement characteristics. Documents US2010076370, US5853397, US8758305 and US2017059376 describe prior art devices.

SUMMARY OF THE INVENTION

[0003] The present description provides a system for detecting a flow of a fluidic medication. The system includes a smart injection port that can be connected to an injection site (such as a "Y Site" or stopcock) for manually administered intravenous injections. The system includes two main sub-assemblies: a single-use flow sensor and a reusable base unit, which snap together before use. The single-use flow sensor includes a flow tube subassembly.

[0004] The present invention relates to a priming valve according to independent claim 1. This priming valve for a fluid sensor associated with a medical device includes a valve comprising a fluid flow path, a fluid inlet in a first end of the fluid flow path configured to couple to a fluid outlet of a fluid channel that includes at least one sensor configured to characterize at least one attribute of a fluid, a fluid outlet at a second end of the fluid flow path, a valve seat and a connector that engages the valve seat to prevent the flow of fluid between the fluid inlet and the fluid outlet through the fluid flow path, where the connector is configured to move relative to the valve seat in response to a threshold pressure within the fluid flow path to allow fluid to flow between the fluid inlet and the fluid outlet of the valve through the path of fluid flow.

[0005] According to other examples, the threshold pressure is 5-50 psi.

[0006] The connector comprises a side wall extending between an inlet end and an outlet end of the connector, wherein the valve seat comprises a side wall extending between an inlet end and an outlet end of the valve seat. valve, and wherein at least a portion of the valve seat extends into the connector, such that an internal surface of the side wall of the connector faces an external surface of the side wall of the valve seat.

[0007] The outer surface of the side wall of the valve seat comprises an edge portion extending radially outward from the side wall of the valve seat where the inner surface of the side wall of the connector is slidably and sealingly engaged to the edge portion of the valve seat and the side wall of the valve seat comprises at least one opening.

[0008] According to other embodiments, the edge portion of the valve seat comprises one of the following: a molded edge seal and an O-ring.

[0009] According to other embodiments, an internal surface of the side wall of the valve seat defines a first portion of the fluid flow path that extends from the fluid inlet of the valve to at least one opening in the side wall of the valve. valve seat, where the at least one opening in the side wall of the valve seat is located in a direction towards the fluid outlet of the valve with respect to the edge portion of the valve seat, and where the inner surface of the side wall of the connector and the external surface of the side wall of the valve seat define a second portion of the fluid flow path that extends from the opening toward the fluid outlet of the valve.

[0010] According to other embodiments, the connector is configured to move axially away from the inlet end of the valve seat in a direction towards the outlet end of the valve seat in response to the pressure of threshold inside the fluid flow path to allow fluid to flow between the fluid inlet and fluid outlet of the valve.

[0011] According to other embodiments, a portion of the side wall of the connector extends radially inward at the inlet end of the connector.

[0012] the external surface of the side wall of the valve seat comprises at least one stop surface extending radially outward from the side wall of the valve seat, where the at least one stop surface is configured to engage the portion of the side wall of the connector that extends radially inward to prevent further axial movement of the connector from the inlet end of the valve seat toward the outlet end of the valve seat.

[0013] According to other embodiments, the inner surface of the side wall of the connector comprises at least one retainer extending radially inward from the side wall.

[0014] According to other embodiments, the external surface of the side wall of the valve seat comprises at least one abutment surface extending radially outward from the side wall, wherein the at least one abutment surface is configured to engage at least a retainer to prevent further axial movement of the connector from the inlet end of the valve seat towards the outlet end of the valve seat.

[0015] According to other embodiments, the external surface of the side wall of the valve seat comprises at least one additional stop surface extending radially outward from the side wall, where the at least one additional stop surface is located on a direction towards the inlet end of the valve seat with respect to the at least one stop surface and wherein the at least one additional stop surface is configured to engage at least one retainer to prevent axial approach of the connector towards the inlet end of the valve seat in a direction opposite to the outlet end of the valve seat.

[0016] According to other embodiments, the valve further comprises an additional fluid flow path between the fluid inlet and the fluid outlet of the valve.

[0017] According to other embodiments, the inner surface of the side wall of the connector comprises an angled surface extending radially inward towards the outlet end of the connector, where the outer surface of the side wall of the valve seat comprises a valve seat surface and wherein the angled surface of the connector engages the valve seat surface of the valve seat to prevent fluid flow between the fluid inlet and the fluid outlet via the fluid flow path.

[0018] According to other embodiments, the valve comprises a connection at the fluid outlet at the second end of the fluid flow path configured to connect to an inlet configured to supply the fluid from the deliverable fluid source to a fluid path that provides the fluid to said medical device.

[0019] According to one embodiment of the present invention, a flow sensor subassembly for detecting the flow of a fluidic medication may include at least one sensor of a fluid port configured to characterize at least one attribute of a fluid within a source. of deliverable fluid, the fluid port comprising: a fluid channel, a fluid inlet at a first end of the fluid channel configured to couple to an outlet of a source of deliverable fluid and a fluid outlet at a second end of the channel of fluid; and a priming valve connected to the fluid outlet at the second end of the fluid channel, wherein the priming valve is configured to prevent flow of fluid from the fluid outlet at the second end of the fluid channel when closed and wherein the priming valve is configured to open to allow fluid flow from the fluid outlet at the second end of the fluid channel in response to a threshold pressure within the fluid channel.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The aforementioned features and advantages and other features and advantages of this description, as well as the manner in which they are obtained, will become more apparent and the description itself will be better understood by referring to the following descriptions of examples of the description taken in combination with the attached drawings, where:

The fig. 1 is a perspective view in the distal direction of a flow sensor system according to an example of the present invention.

The fig. 2 is a perspective view in the distal direction of a flow sensor system according to an example of the present invention.

The fig. 3 is an exploded perspective view of a flow sensor of a flow sensor system according to an example of the present invention.

The fig. 4 is a perspective view of a flow sensor of a flow sensor system according to an example of the present invention.

The fig. 5 is a graph showing the signal level of a flow sensor of a flow sensor system as a function of time according to an exemplary case.

The fig. 6 is a graph showing the signal level of a flow sensor of a flow sensor system as a function of time according to another exemplary case.

The fig. 7 is an exploded perspective view of a flow sensor system according to an example of the present invention.

The fig. 8 is a schematic view of a priming valve according to an example of the present invention.

The fig. 9 is a schematic view of a priming valve according to an example of the present invention.

The fig. 10 is an exploded perspective view of a priming valve according to an example of the present invention.

The fig. 11 is a schematic view of a priming valve according to an example of the present invention.

The fig. 12 is a schematic view of a priming valve according to an example of the present invention.

[0021] Corresponding reference characters indicate corresponding parts throughout the various views. The exemplifications set forth in this invention illustrate exemplary examples of the description and such exemplifications should not be construed as limiting the scope of the description in any way.

DETAILED DESCRIPTION

[0022] The following description is provided to enable those skilled in the art to make and use the described examples contemplated to carry out the invention. Various modifications, equivalents, variations and alternatives, however, will continue to be readily apparent to those skilled in the art.

[0023] For the purposes of the description below in this invention, the terms "top", "bottom", "right", "left", "vertical", "horizontal", "top", "bottom" , "lateral", "longitudinal" and derivatives thereof will refer to the invention as oriented in the figures of the drawings. However, it should be understood that the invention may assume various alternative variations, except when expressly specified otherwise.

[0024] As used in the specification and claims, the singular form of "a", "an" and "the", "the" include plural referents unless the context clearly indicates otherwise.

[0025] As used in this invention, "proximal" refers to a part or direction located far or further away from a patient (upstream), while "distal" refers to a part or direction located towards or closer of a patient (downstream). Likewise, in this invention, a "pharmacological substance" is used in an illustrative and non-limiting manner to refer to any substance injectable into the body of a patient for any purpose. "Patient" refers to any being, human or animal. "Doctor" refers to any person or thing that administers treatment, for example, a nurse, a doctor, an artificial intelligence, a caregiver, or even self-treatment.

[0026] As used in this invention, the phrase "inherently hydrophobic" refers to a surface that naturally excludes water molecules rather than through a drying process, such as hot air drying.

[0027] Unless otherwise indicated, all intervals or relationships described in this invention will be understood to encompass each and every subinterval or subrelationship subsumed within them. For example, an interval or ratio expressed as "1 to 10" will be deemed to include any and all subintervals between (and including) the minimum value of 1 and the maximum value of 10; that is, all subintervals or subrelations that begin with a minimum value of 1 or more and end with a maximum value of 10 or less, such as, but not limited to, between 1 and 6.1, between 3.5 and 7, 8 and between 5.5 and 10.

[0028] Unless otherwise indicated, it will be understood that all figures expressing quantities used in the specification and/or in the claims are modified, in all cases, by the term "approximately".

flow sensor system

[0029] Figs. 1-4 illustrate an exemplary configuration of a flow sensor system 200 of the present description. Referring to figs. 1-4, a flow sensor system 200 of the present description includes two main assemblies that snap together before use: a flow sensor 210 and a base 220. In one example, the flow sensor 210 may be a single-use flow sensor that can be attached to a reusable base 220. The flow sensor system 200 is a smart injection port. The flow sensor system 200 can be connected to an injection site (a "Y-Site" or stopcock, for example) for manually administered intravenous injections.

[0030] The flow sensor system 200 of the present description can reduce bed medication errors during bolus administration. The flow sensor system 200 of the present disclosure may also provide a record and electronically measure bolus delivery, allowing bolus delivery to be monitored and bolus delivery to be automatically documented as part of a patient's medical record. The flow sensor system 200 of the present disclosure may also provide alerts when a bolus delivery inconsistent with a patient's medical history is about to occur.

[0031] Referring to figs. 1-4, in one example, base 220 is a non-sterile reusable device that houses a battery, a scanner (whether optical, mechanical, inductive, capacitive, proximity, or RFID), electronic components, and a wireless transmitter. In some examples, the base 220 is battery operated and rechargeable. In some examples, each base 220 has a unique serial number printed on or embedded in a surface of the base 220 that may be transmitted to a data system prior to use. The data system may be a local computer or tablet "computer", a mobile phone, another medical device, or a hospital data system.

[0032] Referring to figs. 1-4, in one example, the base 220 may be removably connected to the flow sensor 210 and includes at least one deflectable flange 280 defining an opening to receive at least a portion of the flow sensor 210 therein and to secure the flow sensor 210 within a portion of the base 220 before use. In one example, a pair of tabs 280 secure the flow sensor 210 within the base 220. The wing tabs 280 may be flexible to the extent that they can be deflected outwardly to allow passage of the flow sensor 210. In an For example, the flow sensor 210 is a pre-sterilized disposable device provided with an injection port 130 and a distal tubing connection, such as a Luer tip 109, which may optionally be covered by a Luer plug 108.

[0033] Referring to fig. 3, the flow sensor 210 may include a flow tube subassembly 10 consisting of a flow tube 100 provided with an outlet end 101 and an inlet end 102. The outlet end 101 may be provided in fluid communication with a outlet tube 110 provided with an outlet connection 105 that includes a Luer tip 109 that may optionally be covered by a flow restrictor, as described in this invention. In a preferred example, the outlet connection 105 is a plastic connector with a Luer tip 109; However, any suitable method for injecting the medication into a patient is contemplated in one aspect of an example of the invention. For example, it may be desirable to replace the outlet connection 105 and tubing 110 with a needle for direct injection/infusion into a patient.

[0034] The inlet end 102 may be coupled to the reservoir of a medication pen or to an infusion reservoir. The inlet end 102 of the flow tube 100 may be provided in fluid communication with an injection port 130 and may optionally include a connection, such as a threaded Luer connection 131, that may be coupled to a source of a fluid to be injected. The injection port 130 may be provided with a pierceable septum (not shown in the figures) to maintain sterility before use. In one example, the flow tube 100 comprises a medical grade stainless steel and is approximately 50 mm in length with an internal diameter of 1.0 mm and an external diameter of 1.6 mm.

[0035] In one example, the flow sensor system 200 supports injections with any Luerlock-type syringe or liquid medication container. Additionally, the flow sensor system 200 is designed to operate with syringes that are coded with a special barcode identifier on the Luer collar of the syringe, referred to as "coding." Preferably, coded syringes include commercially available drugs in prefilled syringes with a special barcode that stores information about the drug contained within the syringe. Coded syringes are ready to use, passive and disposable. Coding syringes store the name of the drug and the concentration contained within the syringe. Additional features may also be included, such as the drug font, container size, drug manufacturer font, or drug category color, among others. When a coded syringe is connected to the injection port 130 of the flow sensor 210, a scanner located in the base 220 reads this barcode information and the flow sensor system 200 transmits it wirelessly to the data system. Preferably, 2D barcodes will be added to the syringes during the filling process. The 200 flow sensor system also supports non-coding syringes.

[0036] The present description provides a flow sensor subassembly for detecting the flow of a fluidic medication. The flow sensor 210 also includes a first piezoelectric element or an upstream transducer 150 and a second piezoelectric element or a downstream transducer 151. The first piezoelectric element 150 may be provided with an inlet fitting 180, as shown in FIG. . 3, to couple with the injection port 130. Similarly, the second piezoelectric element 151 may be provided with an outlet fitting 190 to couple to the outlet tube 110. The first and second piezoelectric elements 150 and 151 are configured to transmit between the two an ultrasonic signal indicative of a flow of the fluidic medication in the flow tube 100. In one example, the first piezoelectric element 150 and the second piezoelectric element 151 are annular in shape and surround the flow tube 100 at each corresponding mounting point. .

[0037] The flow sensor 210 includes a first spring contact 750a and a second spring contact 750b. In one example, the spring contacts 750a, 750b are attached to a base 700 provided with circuitry for conducting an electrical signal to and from the spring contacts 750a, 750b to a microprocessor. The first spring contact 750a is in electrical communication with a first piezoelectric element 150 and the second spring contact 750b is in electrical communication with a second piezoelectric element 151. The first spring contact 750a has a first contact force against the first element piezoelectric element 150 and the second spring contact 750b has a second contact force against the second piezoelectric element 151. The first contact force may be equivalent to the second contact force. The first and second piezoelectric elements 150, 151 vibrate due to the passage of fluid flow through the flow tube 100 of the flow sensor 210. The vibration of the first and second piezoelectric elements 150, 151 creates an ultrasonic signal that can be detected and communicated electronically to the microprocessor. The microprocessor is configured to correlate the ultrasonic signal with a fluid flow rate passing through the flow tube 100 and provide a fluid flow rate result to the user.

Preparation procedure for a flow sensor

[0038] Referring to figs. 1-2, the use of a flow sensor system 200 of the present description will now be described. In one example, as the drug is injected, the flow sensor system 200 measures the dosed volume ultrasonically. To improve the transmission of ultrasonic signals in the flow sensor 210, the present description proposes several examples of increasing the fluid pressure in the flow sensor 210.

[0039] During manufacturing, the flow sensor 210 may be calibrated on a calibration bench. For example, a fluid, such as water, is flowed through the flow sensor 210 to calibrate the transmission of ultrasonic signals between the first and second piezoelectric elements 150 and 151. Before packaging the flow sensor 210 for shipment, The flow sensor 210 may be dried, for example by hot air, to remove any residual fluid that may remain in the flow sensor 210. Without wishing to be limited by theory, hot air drying of the fluid path surfaces of the Flow sensor 210 contributes to causing said fluid path surfaces to exhibit their intrinsically hydrophobic characteristics. Thus, when the flow sensor 210 is prepared for use by priming the flow sensor 210 with a priming fluid, the inner surface of the fluid path of the flow sensor 210 may not be completely wetted with the priming fluid. . Because the flow sensor 210 is configured to generate ultrasonic signals corresponding to a flow rate of the fluid through contact with the internal flow path of the flow sensor 210, the intrinsically hydrophobic characteristics of the internal surface of the fluid path contribute to a decrease in the ability of the flow sensor 210 to transmit ultrasonic waves. It has been discovered that wetting the internal surfaces of the flow path passing through the flow sensor 210, such as by increasing a pressure or maintaining a pressure inside the flow path, increases the ultrasonic signal transmission capacity of the flow sensor. 210.

[0040] Referring to fig. 1, a first preparation procedure for the flow sensor 210 will now be described. In this example, the flow sensor system 200 is prepared for use by connecting the injection port 130 of the flow sensor system 200 to a source of deliverable fluid, such as a 900 syringe containing a fluid. In some examples, syringe 900 may contain a priming fluid, such as saline. Before connecting the syringe 900, the injection port 130 is desirably cleaned by wiping the cone according to normal hospital procedure. The syringe 900 can be connected to the injection port 130 by rotating the syringe 900 around its longitudinal axis until the syringe 900 stops, that is, a secure connection is established between the syringe 900 and the injection port 130. The syringe 900 has a plunger 920 for delivering the priming fluid from an interior of the syringe 900 when the plunger 920 is pushed in a distal direction.

[0041] The outlet connection 105 is capped with a flow restrictor, such as a plug 910. In some examples, the plug 910 is configured to interact with the Luer tip 109 of the outlet connection 105. The plug 910 may be connected to the Luer tip 109 by rotating the plug 910 around its longitudinal axis until the plug 910 stops, that is, a secure connection is established between the plug 910 and the Luer tip 109. Once connected to the Luer tip 109, the plug 910 prevents the flow of fluid from the outlet connection 105.

[0042] The plunger 920 of the syringe 900 is then pushed distally to deliver fluid from the syringe 900. Because the plug 910 prevents fluid from flowing out of the outlet connection 105, the priming fluid of the syringe 900 builds up fluid pressure inside the flow sensor 210. In some examples, the fluid pressure increase of 5-50 psi inside the flow sensor 210 can be maintained for a predetermined period of time. . For example, the default time period may be approximately 1-60 seconds.

[0043] As fluid from syringe 900 pressurizes flow sensor 210, flow sensor 210 generates at least a first signal to characterize at least one fluid attribute. In various examples, the at least one attribute may be fluid flow rate and/or fluid pressure. Manually increasing the fluid pressure inside the flow sensor 210, while the outlet connection 105 is capped, helps remove air between the inner surface of the flow path of the flow sensor 210 and the fluid. In this way, the internal surface of the flow path of the flow sensor 210 is completely wetted to allow greater signal transmission. ultrasonic flow sensor 210.

[0044] The pressure exerted on the plunger 920 of the syringe 900 can then be released and the plug 910 is removed from the Luer tip 109. The outlet connection 105 is connected to an inlet of a fluid path (which is not shown in the figures) configured to deliver fluid from a deliverable fluid source, such as syringe 900, to a patient. In some examples, the fluid path may be a catheter configured to connect to a patient. Before connecting the fluid path to the patient, fluid is first expelled from syringe 900 of the fluid path, as during priming of the fluid path. As fluid is delivered from syringe 900, fluid flows through flow sensor 210 and exits the fluid path. In some examples, 2-7 ml of fluid can be administered from the syringe 900 through the fluid path. The flow sensor 210 may generate at least one second signal of the same type as the first signal to characterize at least one attribute of the fluid. For example, the second signal may characterize the pressure and/or flow rate of fluid passing through the flow sensor 210. In some examples, the second signal may increase (i.e., have greater intensity) with respect to the first signal when the internal surfaces of the flow path of the flow sensor 210 completely wetted. For example, the second signal may increase by 120%, 160%, or 180% relative to the first signal, including values in between. The flow sensor 210 is now primed and ready for use in a fluid administration procedure.

[0045] In various examples, the flow sensor 210 may be in communication with a controller 930. The controller 930 may be configured to receive information from the flow sensor 210, such as receiving the at least one first signal and the at least one second signal. . The controller 930 may be configured to determine that the at least one fluid attribute based on data received from the at least one first signal and the at least one second signal matches the at least one condition specified by the at least one rule. For example, the controller 930 may be configured to identify a type of fluid flowing through the flow sensor 210 based on a flow rate of the fluid passing through the flow sensor 210 for a given fluid pressure at a given fluid temperature. Without wishing to be limited by theory, each fluid, such as a fluid medication, has a unique ultrasonic signature as the fluid flows through the flow sensor 210. The ultrasonic signature may be a function of the pressure, temperature, and material composition of the fluid. fluent.

[0046] In various examples, the controller 930 may generate at least one operation modification signal in response to the at least one characterized attribute that matches at least one condition specified by the at least one rule. For example, the controller 930 may execute a flow algorithm based on data representing characteristics or attributes of the fluid flow received from the piezoelectric elements 150, 151. In some examples, the syringe 900 may have indicia that, when read by a reading device of the flow sensor system 200 that is in operational communication with the controller 930, cause the controller 930 to initiate a predetermined operational cycle. In some examples, these indicia may be a 2D or 3D barcode, a QR code, or any other indicia capable of storing information that, when read by a reading device of the flow sensor system 200, is configured to be interpreted as a set of instructions that you want the controller 930 to perform. For example, the indicia, when read by the reading device, may cause the controller 930 to initiate a priming cycle to prime the flow sensor 210. In some examples , the priming cycle may comprise generating at least one signal, such as a first signal and a second signal described in this invention.

[0047] The controller 930 may transmit, via a transmitter (not shown in the figures), the operation modification signal to at least one device. In some embodiments, if a fluid type is determined to be a different type of a desired fluid type, or if a flow rate is determined to be a different flow rate than a desired flow rate, the controller 930 may transmit an operation modification signal. to a display and/or a data processing module that causes the module to display an alarm or alert or causes the module to transmit a signal back to system 200 that stops fluid flow. The controller 930 may further control the wireless transmitter to transmit injection data representing a type of medication, a dose of a medication, and/or a duration of a dose of a medication to the display and/or the data processing module. data. In some embodiments, the controller 930 may automatically transmit data to the module in response to an automated injection.

[0048] Referring to fig. 5, a graph is shown representing a percentage of the signal intensity of five flow sensors 210 as a function of time according to an example. Each flow sensor 210 was initially calibrated using a standard calibration routine. The signal readings from each of the flow sensors 210 after calibration are shown as point A on the graph. The flow sensors 210 were then dried with hot air and flushed with priming fluid without being pressurized. Ultrasonic signal transmission readings were then recorded, shown as point B on the graph. From the graph in fig. 5, it can be easily observed that the signal intensity decreases for each of the flow sensors 210 after drying the flow sensors 210 with hot air. To increase the signal level, each flow sensor 210 was covered with a 910 plug and pressurized with a priming fluid, such as saline, for 60 seconds. Once the pressurization period was completed, another signal reading was taken. Point C in fig. 5 illustrates that the signal level increases from point B after pressurizing the flow sensors 210 with a priming fluid.

[0049] Referring to fig. 2, instead of covering the outlet connection 105 with a plug 910, as described in this invention with reference to FIG. 1, the outlet connection 105 may be connected to a vented flow restrictor, such as a vented plug 940. In some examples, the vented plug 940 may be a needle with an internal diameter small enough to be capable of generate back pressure on the flow sensor 210 when fluid is supplied from the syringe 900. For example, the vented plug 940 may be a needle with an output of approximately 30 G (0.16 mm internal diameter). In other examples, the vented plug 940 may have an internal diameter of 0.1-0.2 mm. The priming fluid supplied from the syringe 900 builds up back pressure inside the flow sensor 210. In some examples, the increase in fluid pressure of 5-50 psi inside the flow sensor 210 can be maintained for a period of time. of predetermined time. For example, the default time period may be approximately 1-60 seconds.

[0050] As fluid from syringe 900 pressurizes flow sensor 210, flow sensor 210 generates at least a first signal to characterize at least one fluid attribute. In various examples, the at least one attribute may be fluid flow rate and/or fluid pressure. Manually increasing the fluid pressure inside the flow sensor 210, while the outlet connection 105 is capped, helps remove air between the inner surface of the flow path of the flow sensor 210 and the fluid. In this way, the internal surface of the flow path of the flow sensor 210 is completely wetted to allow greater transmission of ultrasonic signals from the flow sensor 210.

[0051] The pressure exerted on the plunger 920 of the syringe 900 can then be released and the vented cap 940 is removed from the Luer tip 109. The outlet connection 105 is connected to an inlet of a fluid path (which not shown in the figures) configured to deliver fluid from a deliverable fluid source, such as syringe 900, to a patient. In some examples, the fluid path may be a catheter configured to connect to a patient. Before connecting the fluid path to the patient, fluid is first expelled from syringe 900 of the fluid path, as during priming of the fluid path. As fluid is delivered from syringe 900, fluid flows through flow sensor 210 and exits the fluid path. In some examples, 2-7 ml of fluid can be administered from the syringe 900 through the fluid path. The flow sensor 210 may generate at least one second signal of the same type as the first signal to characterize at least one attribute of the fluid. For example, the second signal may characterize the pressure and/or flow rate of fluid passing through the flow sensor 210. In some examples, the second signal may increase (i.e., have greater intensity) with respect to the first signal when the internal surfaces of the flow path of the flow sensor 210 completely wetted. For example, the second signal may increase by 120%, 160%, or 180% relative to the first signal, including values in between. The flow sensor 210 is now primed and ready for use in a fluid administration procedure.

[0052] Referring to fig. 6, a graph is shown representing the signal level of three flow sensors 210 (marked 1, 2, 3) as a function of time according to another example. Each flow sensor 210 was provided with a vented cap 940 fitted with a 30 G needle. A signal count (Point D) was recorded during an administration of 2 ml of fluid from the syringe 900. The vent plug 940 of each flow sensor 210 and a signal count illustrative of a pressure drop was recorded (Point E). From the graph in fig. 6, it can be easily seen that the signal intensity decreases for each of the flow sensors 210 after removing the vented cap 940 from the flow sensors 210. After removing the vented cap 940, 7 ml were administered of fluid from syringe 900 through each flow sensor 210. During this stage, the signal count increased and stabilized at a high value (Point F). A signal level from a fourth flow sensor 210 (marked 4 in FIG. 6), which has been primed without using the vented cap 940, is shown as a comparative example. The signal intensity of the fourth flow sensor 210 is significantly lower than a signal intensity of the flow sensors 210 that were prepared using the vented cap 940 in a manner described in this invention with reference to FIG. 2.

Flow Sensor System Relief Valve

[0053] Referring to fig. 7, instead of covering the outlet connection 105 with a plug 910, as described in this invention with reference to FIG. 1, or a vented flow restrictor, such as a vented cap 940 described in this invention with reference to FIG. 2, the outlet connection 105 may be connected to a priming valve 950 as shown in FIG. 7. In some examples, the priming valve 950 is configured to interact with the Luer tip 109 of the outlet connection 105. The priming valve 950 may be connected to the Luer tip 109 by rotating the priming valve 950 about its longitudinal axis. until the priming valve 950 stops, that is, a secure connection is established between the priming valve 950 and the Luer tip 109.

[0054] Once connected to the Luer tip 109, the priming valve 950, when closed, prevents the flow of fluid from the outlet connection 105 as described in more detail in this invention. Priming valve 950 It is configured to open to allow fluid flow from the outlet connection 105 in response to a threshold pressure within the flow sensor 210. For example, the outlet tube 110 includes a fluid channel between a fluid inlet in fluid communication with the outlet end 101 of the flow tube 100 of the flow sensor subassembly 10 and the outlet connection 105, and the priming valve 950 connected to the outlet connection 105 can be configured to open to allow flow of the fluid from the outlet connection 105 in response to a threshold pressure within the fluid channel of the outlet pipe 110.

[0055] Now referring to figs. 8 and 9, the priming valve 950 includes a fluid flow path 952, a fluid inlet 954 at a first end of the fluid flow path 952 configured to couple to the outlet connection 105, a fluid outlet 956 at a second end of the fluid flow path 952, a valve seat 970 and a connector 980 that engages the valve seat 970 to prevent fluid flow between the fluid inlet 954 and the fluid outlet 956 through of the fluid flow path 952. The connector 980 is configured to move relative to the valve seat 970 in response to a threshold pressure within the fluid flow path 952 to allow fluid flow between the inlet of fluid 954 and the fluid outlet 956 of the priming valve 950 through the fluid flow path 952. In some implementations, the threshold pressure may be 5-50 psi. For example, connector 980 may be configured to remain engaged with valve seat 970 until a pressure of 50 psi is present in fluid flow path 952 that causes connector 980 to move relative to valve seat 970.

[0056] The valve seat 970 includes a side wall 972 that extends between an inlet end 972a and an outlet end 972b of the valve seat 970. The connector 980 includes a side wall 982 that extends between an inlet end 982a and an outlet end 982b of the connector 980. In some implementations, the side walls 972, 982 may be cylindrical side walls that form a cylindrical-shaped valve seat 970 and a cylindrical-shaped connector 980. At least a portion of the seat Valve 970 extends inside connector 980, for example, coaxially inside connector 980 as shown in FIGS. 8 and 9, so that an internal surface 983a of the side wall 982 of the connector 980 faces an external surface 973b of the side wall 972 of the valve seat 970.

[0057] The external surface 973b of the side wall 972 of the valve seat 970 comprises an edge portion 974 that extends radially outward from the side wall 972 of the valve seat 970. For example, a diameter of the valve seat 970 at the edge portion 974 is greater than a diameter of the remainder of the valve seat 970. The inner surface 983a of the side wall 982 of the connector 980 is slidably and tightly coupled to the edge portion 974 of the valve seat 970. For example, the edge portion 974 of the valve seat 970 may include a molded edge gasket, for example, as shown in FIG. 10, or an O-ring configured to form a fluid-tight seal with the inner surface 983a of the side wall 982 of the connector 980, while allowing the side wall 982 of the connector 980 to slide along the portion of edge 974.

[0058] An internal surface 973a of the side wall 972 of the valve seat 970 defines a first portion of the fluid flow path 952 that extends from the fluid inlet 954 of the priming valve 950 to at least one opening 990 in the side wall 972 of the valve seat 970. The at least one opening 990 in the side wall 972 of the valve seat 970 is located in a direction towards the fluid outlet 956 of the priming valve 950 with respect to the portion of edge 974 of valve seat 970. For example, as shown in FIGS. 8 and 9, two openings 990 are located on opposite sides of the side wall 972 and to the right of the edge portion 974 in the direction of the fluid outlet 956. The evenly spaced openings, such as the two openings 990 shown in the fig. 8 and 9, allow the pressure in the fluid flow path to be more evenly distributed inside the priming valve 970 and in the connector 980. The inner surface 983a of the side wall 982 of the connector 980 and the outer surface 973b of the side wall 972 of the valve seat 970 define a second portion of the fluid flow path 952 that extends from the opening or openings 990 toward the fluid outlet 956 of the priming valve 950.

[0059] The connector 980 is configured to move axially away from the inlet end 972a of the valve seat 970 in a direction toward the outlet end 972b of the valve seat 970 in response to the threshold pressure within the flow path. of fluid 952 to allow fluid to flow between the fluid inlet 954 and the fluid outlet 956 of the valve 950 through the fluid flow path 952.

[0060] In some examples, a portion of the side wall 982 of the connector 980 may extend radially inward into the inlet end 982a of the connector 980. For example, as shown in FIGS. 8 and 9, the retainer 984 may extend radially inward at the inlet end 982a of the connector 980. The retainer 984 extends radially inward more than the edge portion 974 extends radially outward. The external surface 973b of the side wall 972 of the valve seat 970 comprises at least one abutment surface 976 extending radially outward from the side wall 972 of the valve seat 970. For example, a height of the edge portion 974 oriented toward the fluid inlet 954 of the priming valve 950 may form the at least one stop surface 976. The at least one stop surface 976 is configured to engage the retainer 984 to prevent further axial movement of the connector 980 from the end. valve seat inlet 972a 970 towards the outlet end 972b of the valve seat 970. For example, the connector 980 is allowed to move relative to the valve seat 970 a distance sufficient to open the fluid flow path 952 at the fluid outlet 956 of the priming valve 950 to a desired or predetermined width, (e.g., to achieve a desired flow rate based on the threshold pressure in the fluid flow path 952 and/or a flow rate and volume of a fluid supplied/being desired to supply through the fluid flow path 952), after which further movement of the connector 980 in that direction is prevented by engaging the retainer 984 to the at least one stop surface 956. The retainer 984 can be formed by applying heat and/or ultrasonic waves to the side wall 982 of the connector 980 to extend the side wall 982 radially inward.

[0061] In another example, as shown in fig. 11, the inner surface 983a of the side wall 982 of the connector 980 may include at least one retainer 986 extending radially inward from the side wall 982. The at least one retainer 986 may be located at any position along the side wall 982 between the inlet end 982a of the side wall 982 and the edge portion 974 of the valve seat 970 when the priming valve 950 is in the closed position. The at least one stop surface 976 is configured to engage the at least one retainer 986 to prevent further axial displacement of the connector 980 of the inlet end 972a of the valve seat 970 toward the outlet end 972b of the valve seat 970. A location of the at least one retainer 986 may be selected to allow displacement of the connector 980 relative to the valve seat 970 a distance sufficient to open the fluid flow path 952 at the fluid outlet 956 of the priming valve 950 until a desired or predetermined width, (for example, to achieve a desired flow rate as a function of the threshold pressure in the flow path 952 and / or a flow rate and volume of a fluid supplied / to be supplied through the flow path 952 fluid flow 952, after which further displacement of the connector 980 is prevented by engaging the retainer 984 to the at least one stop surface 956.

[0062] In one implementation, the external surface 973b of the side wall 972 of the valve seat 970 may include at least one additional stop surface 978 that extends radially outward from the side wall 972. The at least one stop surface Additional 978 is located in a direction toward the inlet end 972a of valve seat 970 with respect to the at least one stop surface 976. The at least one additional stop surface 978 is configured to engage the at least one retainer 986 to prevent axial displacement of the connector 980 towards the inlet end 972a of the valve seat 970 in a direction opposite to the outlet end 972a of the valve seat 970. The at least one retainer 986 and the additional stop surface 978 can be configured so that, when a predetermined pressure or threshold pressure is applied to the fluid flow path 952, the at least one retainer may overcome the additional stop surface 978, for example, by deforming the additional stop surface 978, the retainer 986 and/or the side wall 982 of the connector 980, allowing a further axial movement of the connector 980 from the inlet end 972a of the valve seat 970 in the direction towards the outlet end 972b of the valve seat 970. After exceeding the additional stop surface 978, the engagement of an opposite face of the additional stop surface 978 to at least one detent 976 may act to prevent the connector 980 from returning to the closed position by preventing axial displacement of the connector towards the input end 972a of the valve seat 970 away from the outlet end 972b of the valve seat 970. It should be noted that it may be beneficial to form the connector 980 as two separate pieces, for example, as shown in FIG. 11, if retainers 986 are included to retain the valve seat 970, both separate pieces must be joined by welding after the valve seat 970 is assembled at the inlet end 982a (left half in Fig. 11) of the connector.

[0063] In some examples, the priming valve 950 may include an additional fluid flow path 992 between the fluid inlet 954 and the fluid outlet 956 of the priming valve 950. The additional fluid flow path 992 may sized and shaped to provide a visual indication of fog formation and/or to control back pressure within the fluid flow path 952. In some implementations, the additional fluid flow path 992 may be a needle with a small enough internal diameter to be able to generate back pressure in the flow sensor 210 when fluid is supplied from the syringe 900. For example, the additional fluid flow path 992 may be a needle with an output of approximately 30 G ( 0.16mm internal diameter). In other examples, the additional fluid flow path 992 may have an internal diameter of 0.1-0.2 mm. The priming fluid supplied from the syringe 900 builds up back pressure inside the flow sensor 210. In some examples, the increase in fluid pressure of 5-50 psi inside the flow sensor 210 can be maintained for a period of time. of predetermined time. For example, the default time period may be approximately 1-60 seconds.

[0064] The inner surface 983a of the side wall 982 of the connector 980 comprises an angled surface 987 that extends radially inward toward the outlet end 982b of the connector 980 and beyond the outlet end 972b of the valve seat 970 The outer surface 973b of the side wall 972 of the valve seat 970 includes a valve seat surface 977 and the angled surface 987 of the connector 980 may engage the valve seat surface 977 of the valve seat 970 to prevent fluid flow between the fluid inlet 954 and the fluid outlet 956 via the fluid flow path 952. The priming valve 950 may include a valve outlet connection 999 at the fluid outlet 954 at the second end of the fluid flow path 952 configured to connect to an inlet configured to supply the fluid from the source of deliverable fluid to a fluid path that provides the fluid to a medical device. For example, the connection Valve outlet 999 can be a Luer-Lock connection or a Luer Slip connection.

Procedure for preparing a flow sensor with a relief valve

[0065] The priming valve 950 can be used in place of the plug 910 or the vented plug 940 in the use of a flow sensor system 200 of the present description as described in this invention in the section entitled "Procedure preparation of a flow sensor"; Accordingly, its use in this invention is only briefly described below. For example, as fluid from syringe 900 pressurizes flow sensor 210, flow sensor 210 generates at least a first signal to characterize at least one fluid attribute. In various examples, the at least one attribute may be fluid flow rate and/or fluid pressure. Manually increasing the fluid pressure inside the flow sensor 210, while the outlet connection 105 is capped, helps remove air between the inner surface of the flow path of the flow sensor 210 and the fluid. In this way, the internal surface of the flow path of the flow sensor 210 is completely wetted to allow greater transmission of ultrasonic signals from the flow sensor 210.

[0066] When the fluid pressure inside the flow sensor 210 reaches the threshold pressure of the priming valve 950, which up to this point was closed to prevent fluid flow from the outlet connection 105, the priming valve The priming valve is opened to allow fluid flow from the outlet connection 105. The priming valve is shaped and configured such that the threshold pressure assumes that the inner surface of the flow path of the flow sensor 210 is completely wetted to allow further transmission of ultrasonic signals from the flow sensor 210 before the priming valve 950 opens to release pressure. In some examples, increasing the fluid pressure of 5-50 psi within the flow sensor 210 may be maintained for a predetermined period of time before reaching the threshold pressure. For example, the default time period may be approximately 1-60 seconds. Opening of the priming valve 950 may provide an indication to a physician that sufficient pressure has been achieved within the flow sensor 210 to ensure that the flow sensor 210 is completely wetted.

[0067] The pressure exerted on the plunger 920 of the syringe 900 can then be released and the valve outlet connection 999 is connected to an inlet of a fluid path (not shown in the figures) configured to supply fluid from a source of fluid deliverable, such as syringe 900, to a patient. Alternatively, after the pressure exerted on the plunger 920 of the syringe 900 is released and the priming valve 950 can be removed from the Luer tip 109, and the outlet connection 105 is connected to an inlet of a fluid path (not appears in the figures) configured to deliver fluid from a deliverable fluid source, such as syringe 900, to a patient. In some examples, the fluid path may be a catheter configured to connect to a patient. Before connecting the fluid path to the patient, fluid is first expelled from syringe 900 of the fluid path, as during priming of the fluid path. This can be done with the priming valve still connected to the outlet connection 105, providing clinicians with additional ease of use. As fluid is delivered from syringe 900, fluid flows through flow sensor 210 and exits the fluid path. In some examples, 2-7 ml of fluid can be administered from the syringe 900 through the fluid path. The flow sensor 210 may generate at least one second signal of the same type as the first signal to characterize at least one attribute of the fluid. For example, the second signal may characterize the pressure and/or flow rate of fluid passing through the flow sensor 210. In some examples, the second signal may increase (i.e., have greater intensity) with respect to the first signal when the internal surfaces of the flow path of the flow sensor 210 completely wetted. For example, the second signal may increase by 120%, 160%, or 180% relative to the first signal, including values in between. The flow sensor 210 is now primed and ready for use in a fluid delivery procedure. Flow sensor system use procedure

[0068] To use a primed flow sensor system 200, a user connects the flow sensor 210 to the base 220 by first attaching the flow sensor 210 (on the tube side) and the front sections of the base 220 and, then joining both. Preferably, an audible click will be heard to indicate a secure connection between the flow sensor 210 and the base 220. In one example, connecting the flow sensor 210 to the base 220 automatically turns on the flow sensor system 200. In an For example, connection of flow sensor 210 to base 220 is verified by a flashing light on base 220. In other examples, other indicators may be used.

[0069] The flow sensor system 200 is now ready for intravenous medication administration. In one example, in the event that a flow sensor system 200 fails (excluding the intravenous fluid line), the flow sensor system 200 will continue to allow administration of a standard medication or fluid through the port.

[0070] Next, the administration of an injection using the flow sensor system 200 will be discussed. First, the injection port 130 is cleaned by wiping the cone according to normal hospital procedure. A syringe 900 can then be connected to the injection port 130 of the flow sensor 210 by fully rotating the syringe 900 until the syringe 900 stops, i.e., a secure connection is established between the syringe 800 and the injection port 130. Ideally, the caregiver should double check the name and concentration of each medication in the syringe 900 before connecting it to the injection port 130 to ensure that the correct medication is administered.

[0071] The flow sensor 210 may be arranged after using the flow sensor 210 to detect the flow of at least one fluidic medication. The flow sensor base 220 can be used with a plurality of different flow sensors 210.

[0072] Although this disclosure has been stated to include exemplary designs, the present disclosure may be further modified within the scope of this disclosure. This application is therefore intended to cover any variation, use or adaptation of the description using its general principles. Furthermore, this application is intended to cover such deviations from the present description that fall within known or customary practice in the art to which this description belongs and that fall within the limits of the appended claims.

Claims (15)

1. A priming valve (950) for a fluid sensor (210) associated with a medical device, comprising: a valve (950) comprising a fluid flow path (952), a fluid inlet (954) at a first end of the fluid flow path (952) configured to couple to a fluid outlet of a channel fluid including at least one sensor configured to characterize at least one attribute of a fluid, a fluid outlet (956) at a second end of the fluid flow path (952), a valve seat (970) and a connector (980) which engages the valve seat (970) to prevent fluid flow between the fluid inlet (954) and the fluid outlet (956) through the fluid flow path (952), where the Connector (980) is configured to move relative to the valve seat (970) in response to a threshold pressure within the fluid flow path (952) to allow fluid to flow between the fluid inlet (954). ) and the fluid outlet (956) from the valve (950) through the fluid flow path (952), characterized because The connector (980) comprises a side wall (982) extending between an inlet end (982a) and an outlet end (982b) of the connector (980), where the valve seat (970) comprises a side wall (982b). 972) extending between an inlet end (972a) and an outlet end (972b) of the valve seat (970), where at least a portion of the valve seat (970) extends into the connector (980). ) so that an internal surface (983a) of the side wall (982) of the connector (980) is oriented to an external surface (973b) of the side wall (972) of the valve seat (970), where the external surface (973b) of the side wall (972) of the valve seat (970) comprises an edge portion (974) extending radially outward from the side wall (972) of the valve seat (970), where the inner surface (983a) of the side wall (982) of the connector (980) is slidably and tightly coupled to the edge portion (974) of the valve seat (970) and where the side wall (972) of the valve seat ( 970) comprises at least one opening (990). 2. The priming valve (950) according to claim 1, wherein the threshold pressure is 34.4738-344.738 kPa (5-50 psi). 3. The priming valve (950) according to claim 1, wherein the valve (950) further comprises an additional fluid flow path (952) between the fluid inlet (954) and the fluid outlet (956). of the valve (950). 4. The priming valve (950) according to claim 1, wherein the internal surface (983a) of the side wall (982) of the connector (980) comprises an angled surface (987) that extends radially inwardly towards the outlet end (982b) of the connector (980), where the external surface (973b) of the side wall (972) of the valve seat (970) comprises a valve seat surface (977) and where the angled surface (973b) 987) of the connector (980) engages the valve seat surface (977) of the valve seat (970) to prevent fluid flow between the fluid inlet (954) and the fluid outlet (956) through of the fluid flow path (952). 5. The priming valve (950) according to claim 1, wherein the valve (950) comprises a connection (999) at the fluid outlet (956) at the second end of the fluid flow path (952) configured to connect to an inlet configured to supply the fluid from the source of deliverable fluid to a fluid path that provides the fluid to said medical device. 6. A flow sensor subassembly for detecting the flow of a fluidic medication comprising: at least one sensor of a fluid port configured to characterize at least one attribute of a fluid within a source of deliverable fluid, comprising the port of fluid: a fluid channel, a fluid inlet at a first end of the fluid channel configured to couple to an outlet of a deliverable fluid source, and a fluid outlet at a second end of the fluid channel; and the priming valve (950) of claim 1 connected to the fluid outlet at the second end of the fluid channel, wherein the priming valve (950) is configured to prevent the flow of fluid from the fluid outlet in the second end of the fluid channel when closed, and where the priming valve (950) is configured to open to allow flow of fluid from the fluid outlet at the second end of the fluid channel in response to a threshold pressure at the interior of the fluid channel. 7. The flow sensor subassembly according to claim 6, wherein the priming valve (950) is a priming valve (950) according to any of claims 2-5. 8. A procedure for preparing a fluid sensor (210) associated with a medical device, the procedure comprising: connecting the priming valve (950) of claim 1 to a fluid outlet of the fluid sensor (210), where the priming valve (950) is configured to prevent the flow of fluid from the fluid outlet of the fluid sensor (210) when closed, and where the priming valve (950) is configured to open to allow the flow of fluid from the fluid outlet of the fluid sensor (210) in response to a threshold pressure within a fluid channel of the fluid sensor (210), the fluid sensor (210) comprising: the fluid channel, a fluid inlet (954) at a first end of the fluid channel configured to couple to an outlet of a deliverable fluid source, and the fluid outlet at a second end of the fluid channel; supplying fluid from the deliverable fluid source to the fluid channel through the fluid inlet (954); and pressurizing the fluid in the fluid channel between the fluid inlet (954) and the priming valve (950) to wet an internal surface of the fluid channel with the fluid and reaching the threshold pressure to open the priming valve (950). 950) to allow fluid to flow from the fluid outlet of the fluid sensor (210). 9. The method according to claim 8, further comprising supplying fluid through the fluid channel and generating a signal characterizing at least one attribute of a fluid. 10. The method according to claim 8, wherein the threshold pressure is 34.4738-344.738 kPa (50 psi). 11. The method according to claim 8, wherein the fluid is pressurized for a predetermined period of time at a predetermined pressure before reaching the threshold pressure. 12. The method according to claim 11, wherein the predetermined pressure is 34.4738-344.738 kPa (5-50 psi). 13. The method according to claim 8, wherein the fluid sensor (210) is an ultrasonic fluid sensor. 14. The priming valve according to claim 1, wherein the connector (980) is configured to move axially away from the inlet end (972a) of the valve seat (970) in a direction towards the outlet end (972b) of the valve seat. valve (970) in response to the threshold pressure within the fluid flow path (952) to allow fluid to flow between the fluid inlet (954) and the fluid outlet (956) of the valve (952) 950), where a portion of the side wall (982) of the connector (980) extends radially inward at the inlet end (982a) of the connector (980), where the external surface (973b) of the side wall (972 ) of the valve seat (970) comprises at least one stop surface (976) extending radially outward from the side wall (972) of the valve seat (970), where the at least one stop surface (976) It is configured to engage the portion of the side wall (982) of the connector (980) that extends radially inward to prevent further axial movement of the connector (980) from the inlet end (972a) of the valve seat (970). in the direction of the outlet end (972b) of the valve seat (970). 15. The priming valve according to claim 1, wherein the connector (980) is configured to move axially away from the inlet end (972a) of the valve seat (970) in a direction towards the outlet end (972b) of the valve seat. valve (970) in response to the threshold pressure within the fluid flow path (952) to allow fluid to flow between the fluid inlet (954) and the fluid outlet (956) of the valve (952) 950), where the internal surface (983a) of the side wall (982) of the connector (980) comprises at least one retainer (986) that extends radially inward from the side wall (982), where the external surface (973b ) of the side wall (972) of the valve seat (970) comprises at least one stop surface (976) extending radially outward from the side wall (972), where the at least one stop surface (976) It is configured to engage at least one retainer (986) to prevent further movement of the connector (980) from the inlet end (972a) of the valve seat (970) towards the outlet end (972b) of the valve seat ( 970), where the external surface (973b) of the side wall (972) of the valve seat (970) comprises at least one additional stop surface (978) extending radially outward from the side wall (972), where the at least one additional stop surface (978) is located in a direction towards the inlet end (972a) of the valve seat (970) with respect to the at least one stop surface (976), and where the at least An additional stop surface (978) is configured to engage the at least one retainer (986) to prevent axial displacement of the connector (980) towards the inlet end (972a) of the valve seat (970) in a direction opposite to the outlet end (972b) of the valve seat (970).